Hospital function latch



Feb; 18,1969 M. M. CHECK 3,428,352

HOSPITAL FUNCTION LATCH Sheet Filed Oct. 25. 1966 INVENTOR M. M. CHECK ATTORNEYS Feb. 18, 1969 M, M. CHECK 3,352

HOSPITAL FUNCTION LATCH Filed Oct. 25. 1966 Sheet 3 of 2 27 25 3| 42 Y, 39 38 @Q Kl INVENTOR M. M. CHECK ATTORNEYS United States Patent O 3,428,352 HOSPITAL FUNCTION LATCH Mathias M. Check, Greenwich, Conn., assignor to Eaton Yale & Towne Inc., Cleveland, Ohio, a corporation of Ohio Filed Oct. 25, 1966, Ser. No. 589,294 US. Cl. 292-359 13 Claims Int. Cl. E051: 13/ Ec 1/12 ABSTRACT OF THE DISCLOSURE A locking washer slides within a knob spindle sleeve of a latch, and is spring pressed in a direction to enter an axial groove in the bearing sleeve of the spindle so as to lock the spindle in bolt retracting position. The bearing sleeve also has a transverse holding surface against which the washer wil move when a push button moves it out of the axial groove. That surface then holds the washer against its spring pressure while the latchbolt projects, and until the spindle again moves to bolt retracting position.

My invention relates to a novel hospital latch of the type adapted to be used on the door to the room of a patient.

It is highly desirable, in order to maintain quiet in a hospital, that movements into and out of patients rooms be possible without the noise incidental to the operation of a latchbolt. For this reason, it is highly desirable that latches used on doors of the class described be so formed that when the latchbolt is once retracted, it is thereafter held retracted. When the bolt is so held, one needs merely push the door to gain entry into a patients room or to pull the door to move out of the room. The door is held in closed position, when not being pulled or pushed, by a door closer.

Under particular conditions, however, the door to a patients room should be latched shut. My invention contributes to the art an extremely positive but simple mechanism that will automatically hold a latchbolt retracted upon its retraction by a knob of the latch, after which the simple operation of a button will release the latchbolt for projection when desired.

As a feature of my invention, I utilize a detent pref erably carried by the lat-ch retracting spindle, and acting automatically when the spindle rotates to latch retracting position to lock the spindle in that position. A push button carried by the knob may be depressed at any time to effect movement of the detent so as to release the spindle and the latchbolt, for the projection of the latchbolt to 3 its normal operating position.

As a further feature, I utilize a detent that is spring pressed so as to slide toward a locking position on a latch retracting spindle. There are means that hold the detent against sliding while the spindle is in a particular position, and that enable the detent to slide automatically to lock the spindle when the spindle is rotated. As a detailed part of this feature, the spring pressure slides the detent in an axial direction toward the outer end of the spindle.

I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows may be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto.

'Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart Patented Feb. 18, 1969 from the spirit and scope of my invention, in order to prevent the appropriation of my invention. by those skilled in the art.

Referring now to the drawings:

FIG. 1 shows a longitudinal section of a latch utilizing my invention.

FIG. 2 shows a cross section on the line 2--2 in FIG. 1.

LFIG. 3 shows a section of a bearing sleeve of the latch, as it would appear on the line 3-3 in. FIG. 2.

FIG. 4 shows an exploded view of parts of my mecha- 1115111.

For the purpose of describing my invention, I show in FIG. 1 of the drawings a rather usual latch housing 10 having opposed inside and outside bearing sleeves 11, 12, and roses 13, 14 threaded on sleeves 11, 12 for mounting the housing in position in a bore 15 formed through a door D. There are inside and outside spindle sleeves 18, 19 that rotate in the bearing sleeves 11, 12, and that are equipped with knobs 16, 17. The spindle sleeves 18, 19 have cam portions 20, 21 coacting with a bolt retractor 22 in housing 10 so that either spindle sleeve when rotated will move retractor 22 to retract to a latchbolt 23. A spring 24 presses retractor 22 to bolt projecting position, acting also through cam portions 20, 21 to press each spindle sleeve 18, 19 toward. a neutral position, as actually shown in FIG. 1. That construction will be well understood by those skilled in the art and -I believe that it need not be further described at this point. It is merely necessary to know here that outside spindle sleeve 19 will rotate on hearing sleeve 12 to retract a latchbolt, and that spindle sleeve 19 is spring pressed toward a neutral position corresponding to the projected position of the latchbolt.

In the novel concept of my invention, I utilize a locking detent 25, shown in FIG. 1 but better seen in FIGS. 2 and 4, that slides in an axial direction relatively to the outside spindle sleeve 19. The locking detent 25 in my preferred construction is a washer having opposed parts of its periphery formed with a lug 26 and a relatively long locking finger 27 that engage longitudinal slots 28 formed on opposed sides of spindle sleeve 19, thus mounting the washer for sliding within sleeve 19. In the position shown in FIGS. 1 and 2, the locking finger 27 lies in a circular groove 30 formed in the inner surface of bearing sleeve 12. By its position in the groove 30, the finger 27 naturally will permit spindle sleeve 19 to rotate. I shall presently refer to a shoulder 30a comprising the outer side of groove 30, that is, the side toward the outer end of sleeve 12. I do not actually wish to be limited by a groove for the finger 27, since it is merely necessary that hearing sleeve 12 be formed with a clear ance portion for finger 27, with a shoulder at the outer side of the clearance portion.

Referring to FIGS. 1 and 4, a coil spring 31 is as sembled between locking washer 25 and a further washer 32 within the spindle sleeve 19. Washer 32 may be similar to locking washer 25 but will not engage the bearing sleeve 12, there merely being two relatively short lugs 33 for engaging the spindle slots 28. Lugs 33 will lie against the inner ends of spindle slots 28 so that Washer 32 will support the inner end of spring 31, as will be understood when considering FIG. 1. Thereby the locking washer 25 will be spring pressed in an axial direction outwardly on spindle sleeve 19, or in other words toward the outside knob 17 It will be recognized that the washer arrangement that I have just described is somewhat like that which is shown in the patent to Paul Kubik, No. 2,983,537. The extremely novel concept in which I utilize that arrangement will be understood as my description proceeds.

Thus, I form the inner surface of hearing sleeve 12 with at least one and preferably two slots 34, shown in FIGS. 2 and 3, that extend from the groove 30 in a direction toward the outer end of spindle sleeve 19. Each of those slots 34 is so displaced from a neutral position of the locking finger 27 that the slot may accept that finger when spindle sleeve 19 rotates to a predetermined bolt retracting position. Further, I equip the outside knob 17 with a push button 35 having a stem 36 extending within the spindle sleeve 19. On the stem 36 are shoulders 37 for engaging a washer 38, so that washer 38 will slide inwardly when push button 35 is depressed. The periphery of washer 38 has opposed lugs 39, FIG. 4, that engage the spindle slots 28 so as to guide that washer on spindle sleeve 36, and acts in a usual way between the button 35 and a knob retainer 41 for pressing the button 35 to a normal outward position. The knob retainer 41 engages openings in the knob sleeve and spindle sleeve for retaining the knob 17, as will be understood, and is simply utilized here as a convenient means of holding the spring 40. I might indicate at this point that I can utilize a spring of the same specifications for the spring 40 and also for the spring 31. However, the spring 31 when assembled in my preferred construction is compressed to a greater extent, and applies very firm pressure to the locking washer 25.

Referring again to FIG. 1, a spacer 42 is assembled between the washer 38 and the locking washer 25, so that the push button 35 when depressed will act directly through washer 38 and spacer 42 to slide the locking Washer 25. In the position shown in FIG. 1, it will be seen that the space between Washers and 38 is longer than is the spacer 42, but that is due to the fact that in FIG. 1 the locking washer 25 is held aligned with groove while an outward movement of push button has permitted washer 38 to move outwardly. Spacer 42 and wash er 38 then are loose, and it may be said that there is lost motion between locking washer 25 and push button 35.

Let us suppose now that the door D is in closed position, with latchbolt 23 projected and engaging a strike. The spindle sleeve 19 is in neutral position, as in FIG. 1, and the locking washer 25 is in aligned relation to the groove 30 in bearing sleeve 12. Moreover, as indicated in phantom in FIG. 3, the locking finger 2.7 of the washer 25 is against the shoulder 30a, so that the pressure of spring 31 cannot move the washer 25 out of aligned relation to groove 30 while spindle sleeve 19 is in neutral position. However. should a person rotate the outside knob 17 so as to retract latchbolt 23 a predetermined amount, the locking finger 27 will rotate into aligned relation to one of the longitudinal grooves 34. Washer 25 then will slide due to its spring pressure, placing its finger 27 in locking position in the particular groove 34, as indicated at 27a in FIG. 3. In so sliding, the locking washer 25 will take up all or nearly all of the lost motion to which I have referred. between washer 25 and push button 3 It will be seen that the lost motion, and also the axial direction in which spring 31 presses, have caused a positive movement of the locking washer 25 to locking position.

While in locking position, the washer 25 will act through the outside spindle sleeve 19 to hold latchbolt 23 retracted, so that there will be no movements of the bolt during opening and closing movements of the door. Should it be desired again to utilize the latchbolt 23, it will merely be necessary to depress the push button 35 so as to place the locking washer 25 in aligned relation to groove 30. The retractor spring 24 then will rotate spindle sleeve 19 to neutral position, moving the locking finger 27 into groove 30 while latchbolt 23 projects. The parts of the latch then are in the operating position shown in FIG. 1.

I believe that the construction and operation of my novel hospital latch will now be understood, and that its advantages will be fully appreciated. Thus, I contribute a atch having a bolt than can be retracted through the operation of either of two knobs, but that will have a very positive and effective action that will lock the \bolt automatically in retracted position once it is retracted by one of the knobs. Thereafter, no manipulation of either knob will cause the bolt to project, though the bolt may again be projected simply through the operation of a button. Due to the very eifective operation of my latch, I am able to reduce to a very great extent the noise that may be incidental to the movements of a hospital door, while allowing the latching function that is necessary. I believe, therefore, that the very considerable value of my invention will be appreciated.

I now claim:

1. In a latch of the class described, a housing, a spindle rotatably mounted in said housing, a latchbolt, means whereby said spindle retracts said latchbolt upon rotation of said spindle relatively to said housing from a neutral position to a retracting position, means including a detent that is spring pressed in an axial direction relatively to th spindle, the latch housing having an axially extending surface toward which said detent moves by its spring pressure whereby to lock said spindle against rotation back to said neutral position upon rotation of said spindle to said retracting position, said spindle then holding said latchbolt retracted, a button manually movable on said spindle from a normal position to an actuated position, and means coacting with said button when said button is moved to actuated position for releasing said spindle from said detent to permit said latchbolt to be projected.

2. In the combination of claim 1, the feature that said button is a push button mounted for depressing movement in the axis of the detent movements.

3. In the combination of claim 1, a spring action in axial direction between said detent and a part on the spindle so as to press said detent toward position locking the spindle.

4. In the combination of claim 1, the feature that said detent is a plate mounted to slide on said spindle.

5. In the combination of claim 4, a spring acting between said plate and a part on the spindle so as to press said plate toward position locking the spindle, and said button being a push button mounted for depressing movement in opposed relation to the axial pressure of said spring.

6. In a latch of the class described, a housing, a spindle rotatably mounted in said housing, a latchbolt, means whereby said spindle retracts said latchbolt upon rotation of said spindle relatively to said housing from a neutral position to a retracting position, a movable detent mounted to rotate with the spindle and having a portion for coacting with said housing, spring means acting between the spindle and detent whereby to press said portion of the detent relatively to the housing, said housing having a holding surface accepting the spring pressure of said detent portion when the spindle is in its neutral position, a locking surface formed in position on the housing to accept said portion of the detent When the spindle rotates to retracting position, so that said detent by its spring pressure will act positively to lock the spindle each time said spindle retracts the bolt, a manually operated button mounted for movement relatively to said spindle, and means whereby said button moves said detent away from said locking surface and into aligned relation to the holding surface to permit the latchbolt to be projected.

7. A combination as set forth in claim 6, including means mounting said detent for sliding in an axial direction on the spindle, said locking surface comprising a groove formed on an inner surface of the housing, and means mounting said spring means in position on the spindle to act in aligned relation to said groove.

8. A combination as set forth in claim 6, including means mounting said detent for sliding in an axial direction on the spindle, said holding surface extending in a transverse direction on the housing, said locking surface of the housing extending toward the outer end of the spindle so as to accept said detent portion when the detent slides outwardly, and said manually operated button being a push button adapted to be depressed in an axial direction on the outer end of the spindle.

9. In a latch of the class described, a housing, a spindle rotatably mounted in said housing, a latchbolt, means whereby said spindle retracts said latchbolt upon rotation of said spindle relatively to said housing from a neutral position to a retracting position, a detent mounted for movement in an axial direction relatively to the spindle and housing, spring means continuously pressing said detent in one axial direction on its mounting, surfaces between which said detent engages on said spindle and housing, including a holding surface in position holding said detent against movement by its spring pressure while the spindle is in one of its neutral and retracting positions, and a locking surface in position to be engaged through the spring pressed movement of the detent while the spindle is in the other of its said positions, whereby to effect positive locking of the spindle upon rotation of the spindle to said other position, a manually operated button mounted for movement in axial direction relatively to the spindle, and means whereby said button moves the detent away from the locking surface to release said spindle for operation of the lat chbolt.

10. A combination as set forth in claim 9, including means so mounting said spring means as to press the detent toward the outer end of the spindle, said locking surface being formed in position toward the outer end of the spindle relatively to said holding surface, and said manually operated button being a push button adapted to be depressed relatively to the outer end of the spindle.

11. A combination as set forth in claim 10, including a sleeve forming said spindle, and a washer assembled within the sleeve and forming said detent, said Washer comprising a finger engaging an axially extending slot in the spindle, said holding surface and said locking surface being surfaces formed to extend transversely on the inner periphery of the housing for coacting with said detent finger, and said spring means being assembled within the spindle and in position acting directly between said washer and a part on the spindle.

12. In a latch of the class described, a housing, a spindle rotatbly mounted in said housing, a latchbolt, means whereby said spindle when rotated retracts said latchbolt, a detent mounted for movement in an axial direction relatively to the spindle and housing, spring means pressing said detent on its mounting toward a position coacting with said housing whereby to lock the spindle against rotation, and manually operated means for moving said detent against its spring pressure to a position releasing said spindle for rotation.

13. A combination as set forth in claim 12, including a sleeve forming said spindle, said detent being assembled within the sleeve and having a portion extending outwardly of said sleeve for coacting with the housing, and said spring means comprising a spring assembled within the sleeve and acting in an axial direction between the detent and a part on said sleeve.

US. Cl. X.R. 

